Methods and arrangements to coordinate communications of different types of devices on a wireless network

ABSTRACT

Logic may coordinate communications of different types of wireless communications devices such as high power and low power wireless communications devices. Logic may coordinate communications by assigning time slots to a low power station (LP-STA) in a management frame such as a beacon transmitted by an access point (AP) associated with the LP-STA. Logic of the high power stations (HP-STAB) may receive the beacon and shepard logic of the HP-STA may defer transmissions by the HP-STA throughout the duration(s) indicated in the beacon from the AP. Logic of the LP-STA may comprise carrier sense multiple access with collision avoidance logic to determine when to transmit a communication. Shepard logic of an HP-STA may detect the communication from the LP-STA and defer transmission of communication during a time duration for the communication by the LP-STA.

BACKGROUND

The present disclosure relates generally to the field of wirelesscommunications technologies. More particularly, the present disclosurerelates to coordination of communications of different types of deviceson a wireless network.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 depicts an embodiment of a wireless network comprising aplurality of communications devices;

FIG. 1A depicts an embodiment of a wireless network comprising highpower stations and low power stations;

FIG. 1B depicts another embodiment of a wireless network comprising highpower stations and low power stations;

FIG. 1C depicts an embodiment of a management frame with a timeinformation element for establishing communications between wirelesscommunication devices;

FIG. 1D depicts an embodiment of a time information element forestablishing communications between wireless communication devices;

FIG. 1E depicts an embodiment of shepard logic for the systemillustrated in FIG. 1;

FIG. 2 depicts an embodiment of an apparatus to coordinatecommunications;

FIG. 3A-C depict embodiments of flowcharts to coordinate communications;and

FIG. 4 depicts an embodiment of a flowchart to coordinate communicationsas illustrated in FIG. 2.

DETAILED DESCRIPTION OF EMBODIMENTS

The following is a detailed description of novel embodiments depicted inthe accompanying drawings. However, the amount of detail offered is notintended to limit anticipated variations of the described embodiments;on the contrary, the claims and detailed description are to cover allmodifications, equivalents, and alternatives as defined by the appendedclaims. The detailed descriptions below are designed to make suchembodiments understandable and obvious to a person having ordinary skillin the art.

Generally, embodiments for coordinating communications of differenttypes of devices on a network are described herein. Embodiments maycomprise logic such as hardware and/or code to coordinate communicationsof different types of wireless communications devices such as high powerwireless communications devices and low power wireless communicationsdevices. Many embodiments coordinate communications by assigning timeslots to a low power station (LP-STA) in a management frame such as abeacon transmitted by an access point (AP) associated with the LP-STA.For instance, the AP may include a time information element in a beacon.The LP-STA may receive the beacon, and parse the time element todetermine a time slot within which to transmit a communication to theAP. In some embodiments, the time information element may include aduration field to identify the duration of the timeslot. In furtherembodiments, the time information element may comprise a device typefield to identify the device type of the low-power devices as beingassociated with the time duration. And, in some embodiments, the timeinformation element may include a periodicity field to indicate multipletime slots or periodic time slots within which the LP-STA may transmit acommunication without interference from a high power device.

In further embodiments, the high power stations (HP-STAs) may receivethe beacon and shepard logic of the HP-STAs may defer high transit powertransmissions by the HP-STAs throughout the duration(s) indicated in thebeacon from the AP.

In some embodiments, the LP-STA may comprise carrier sense multipleaccess with collision avoidance (CSMA/CA) logic to determine when totransmit a communication. The LP-STA may monitor a channel to determineif there is any communications traffic on the channel and, if the LP-STAdoes not sense other traffic on the channel, the LP-STA may initiate acommunication on the channel. In several embodiments, the CSMA/CA logicmay be supplemented by the exchange of a Request to Send (RTS) packetsent by the LP-STA, and a Clear to Send (CTS) packet sent by theintended receiver such as an AP. Thus alerting all nodes within range ofthe sender, receiver or both, to not transmit for the duration of themain transmission. This is known as the IEEE 802.11 RTS/CTS exchange.

In many embodiments, shepard logic of an HP-STA may detect thecommunication from the LP-STA and defer transmission of communicationduring a time duration for the communication by the LP-STA. In furtherembodiments, one or more of the HP-STAs may comprise shepard logic withlogic to transmit time duration information corresponding to the timeallocated to LP-STA transmissions. The time information may also includea periodicity of the time duration. In some embodiments, the timeinformation may be included in a management frame when transmitted.

IEEE 802.11ah is being developed to support two very different types ofdevices in the sub 1 GHz frequency band: 1) a sensor type device and 2)a cellular offloading type device. The sensor device is typicallypowered with a small battery and does not support very high transmitpower. For example, the low power sensor device deployed in an indoorenvironment may operate with 0 dBm (decibels (dB) of the measured powerreferenced to one milliwatt (mW)) transmit power to minimize its powerconsumption. This type of stations can be classified as “low transmitpower STA (LP-STA)”. Note that stations refer generally to any type ofcommunications device and access points refer to a specific type ofstation.

On the other hand, the cellular offloading device is typically operatedin an outdoor environment and supports a transmit power close to themaximum transmit power (e.g. 30 dBm in US) allowed to cover a much widerarea compared to the low power sensor type device. This type of stationscan be classified as “high transmit power STA (HP-STA)”.

The sensitivity of the HP-STA may be significantly less than necessaryfor the HP-STA to detect LP transmissions, potentially causingcollisions. Receive sensitivity is expressed using the version ofdecibel employed in measurements of radio power, the dBm. In the dBmscale, 0 dBm equals 1 mW. Power of 100 mW equals 20 dBm and power of1000 mW (i.e., 1 W) equals 30 dBm. Power levels below 1 mW are expressedas negative number. For example, 0.01 mW would be −20 dBm.

The following discussion includes references to high transmit powertransmissions and devices as well as low transit power transmissions anddevices. For the purposes of clarity, the high power transmissions anddevices will refer to any transmission having a power of more than 10dBm and devices capable of transmissions having a power of more than 10dBm. And the low power transmissions and devices will refer to anytransmission having a power of 10 dBm or less and devices capable oftransmissions having a power of up to 10 dBm.

Various embodiments may be designed to address different technicalproblems associated with coordinating communications of devices. Forinstance, some embodiments may be designed to address one or moretechnical problems such as deferring high transmit power transmissionsthat extend to an LP-STA or LP-AP during a low transmit powertransmission between the LP-STA and LP-AP. The technical problem ofdeferring high transmit power transmissions that extend to an LP-STA orLP-AP during a low transmit power transmission may involve informingHP-STAs and HP-APs of the low power transmission, particularly forsituations in which the HP-STA or HP-AP is unable to detect the lowtransit power transmission due to an insufficient receiver sensitivityfor the low transmit power transmission.

Different technical problems such as those discussed above may beaddressed by one or more different embodiments. For instance, someembodiments that are designed to address deferring high transmit powertransmissions that extend to an LP-STA or LP-AP during a low transmitpower transmission between the LP-STA and LP-AP may do so by one or moredifferent technical means such as a high transmit power transmissionfrom an LP-AP including a time duration during which the HP-STAs andHP-Aps should defer high transmit power transmissions or, in someembodiments, all transmissions. Further embodiments that are designed toinforming HP-STAB and HP-APs of the low transmit power transmission maydo so by one or more different technical means such as shepard logic inthe MAC sublayer logic of an HP-STA or an HP-AP that may inform otherHP-STAs and HP-APs of the time duration of the low transmit powertransmission. In further embodiments, the shepard logic may establish atime duration, one time or periodic, for low transmit powertransmissions by LP-STAs.

Some embodiments implement a 1 Megahertz (MHz) channel bandwidth forInstitute of Electrical and Electronic Engineers (IEEE) 802.11ahsystems. The lowest data rate in such embodiments may be approximately6.5 Megabits per second (Mbps) divided by 20=325 Kilobits per second(Kbps). If two times repetition coding is used, the lowest data ratedrops to 162.5 Kbps. In many embodiments, the lowest PHY rate is usedfor beacon and control frame transmissions. Although lowering the datarate may increase the transmission range, it takes much longer time totransmit a packet. According to one embodiment, the efficiency of theprotocol may enable small battery-powered wireless devices (e.g.,sensors) to use Wi-Fi to connect to the, e.g., Internet with very lowpower consumption.

Some embodiments may take advantage of Wireless Fidelity (Wi-Fi) networkubiquity, enabling new applications that often require very low powerconsumption, among other unique characteristics. Wi-Fi generally refersto devices that implement the IEEE 802.11-2007, IEEE Standard forInformation technology—Telecommunications and information exchangebetween systems—Local and metropolitan area networks—Specificrequirements—Part 11: Wireless LAN Medium Access Control (MAC) andPhysical Layer (PHY) Specifications(http://standards.ieee.org/getieee802/download/802.11-2007.pdf) andother related wireless standards.

Several embodiments comprise access points (APs) for and/or clientdevices of APs or other stations (STAs) such as cellular off-loadingdevices, routers, switches, servers, workstations, netbooks, mobiledevices (Laptop, Smart Phone, Tablet, and the like), as well as sensors,meters, controls, instruments, monitors, appliances, and the like. Someembodiments may provide, e.g., indoor and/or outdoor “smart” grid andsensor services. For example, some embodiments may provide a meteringstation to collect data from sensors that meter the usage ofelectricity, water, gas, and/or other utilities for a home or homeswithin a particular area and wirelessly transmit the usage of theseservices to a meter substation. Further embodiments may collect datafrom sensors for home healthcare, clinics, or hospitals for monitoringhealthcare related events and vital signs for patients such as falldetection, pill bottle monitoring, weight monitoring, sleep apnea, bloodsugar levels, heart rhythms, and the like. Embodiments designed for suchservices generally require much lower data rates and much lower (ultralow) power consumption than devices provided in IEEE 802.11n/ac systems.

Logic, modules, devices, and interfaces herein described may performfunctions that may be implemented in hardware and/or code. Hardwareand/or code may comprise software, firmware, microcode, processors,state machines, chipsets, or combinations thereof designed to accomplishthe functionality.

Embodiments may facilitate wireless communications. Some embodiments maycomprise low power wireless communications like Bluetooth®, wirelesslocal area networks (WLANs), wireless metropolitan area networks(WMANs), wireless personal area networks (WPAN), cellular networks,communications in networks, messaging systems, and smart-devices tofacilitate interaction between such devices. Furthermore, some wirelessembodiments may incorporate a single antenna while other embodiments mayemploy multiple antennas. The one or more antennas may couple with aprocessor and a radio to transmit and/or receive radio waves. Forinstance, multiple-input and multiple-output (MIMO) is the use of radiochannels carrying signals via multiple antennas at both the transmitterand receiver to improve communication performance.

While some of the specific embodiments described below will referencethe embodiments with specific configurations, those of skill in the artwill realize that embodiments of the present disclosure mayadvantageously be implemented with other configurations with similarissues or problems.

Turning now to FIG. 1, there is shown an embodiment of a wirelesscommunication system 1000. The wireless communication system 1000comprises a communications device 1010 that may be wire line andwirelessly connected to a network 1005. The communications device 1010may communicate wirelessly with a plurality of communication devices1030, 1050, and 1055 via the network 1005. The communications device1010 may comprise an access point. The communications device 1030 maycomprise a low power communications device such as a sensor, a consumerelectronics device, a personal mobile device, or the like. Andcommunications devices 1050 and 1055 may comprise low and high powerdevices respectively and may comprise sensors, stations, access points,hubs, switches, routers, computers, laptops, netbooks, cellular phones,smart phones, PDAs (Personal Digital Assistants), or otherwireless-capable devices. Thus, communications devices may be mobile orfixed. For example, the communications device 1010 may comprise ametering substation for water consumption within a neighborhood ofhomes. Each of the homes within the neighborhood may comprise a sensorsuch as the communications device 1030 and the communications device1030 may be integrated with or coupled to a water meter usage meter.

In some embodiments, the communications device 1010 may be an AP ofLP-STAs and may include time information, during which the LP-STAs maytransmit packets, in a frame 1014 such as a beacon frame or othermanagement frame. The time information may comprise a duration, and may,in further embodiments, also include a periodicity of the time duration,and may, in further embodiments, also include a device type indicationto identify the type of device that is assigned to the time duration.For instance, the communications device 1010 may include information ondevice type (e.g. LP-STA) in a device type field of a time informationelement so that other communications devices 1030, 1050, and 1055 thatreceive the information know which type of STAs will be transmittingduring the time duration.

In many embodiments, the management frame 1014 that contains the timeinformation of the time duration and the device type may be transmittedat a high transmit power (HP). Thus, HP-STAs and HP-APs that haveinsufficient sensitivity to detect the low transmit power (LP)transmissions but are sufficiently near that their transmissions cancollide with LP transmissions, can detect and receive the managementframe 1014 from the communications device 1010. In response, low powerdevices, LP-STAs, such as the communications devices 1030 and 1050 maytransmit packets during the time duration indicated in the managementframe 1014 sent by the communications device 1010, the AP of theLP-STAs.

Furthermore, when HP-STAs, such as the communications device 1055, whichmay not hear the transmissions of the LP-STAs, receive the timeinformation in the management frame 1014 transmitted by the AP of theLP-STAs, the HP STAs may defer their transmissions until after the timeduration indicated in the management frames 1014.

To illustrate, the communications device 1010 may transmit a managementframe 1014 identifying a time slot with a time duration, a periodicity,and a device type of LP-STA with a HP transmission. The time duration incombination with the device type may indicate that only LP-STAs maytransmit during the time duration. In other embodiments, the managementframe 1014 may indicate that devices may only transmit at a lowtransmission power.

The communications device 1055 may be an HP-STA and may receive themanagement frame 1014. Shepard logic 1056 of the communications device1055 may defer transmissions, or at least HP transmissions in someembodiments, during the time duration(s).

The communications device 1030 may parse the management frame 1014 todetermine the time duration associated with LP-STA and, as an LP-STA,may transmit a frame 1034 during the time duration indicated in themanagement frame 1014. The communications device 1050 may also be anLP-STA and may comprises CSMA/CA logic 1051 to monitor a channel todetermine whether the channel is free to transmit. In situations whereinthe communications devices 1030 and 1050 are sufficiently close tointerfere with each others' communications, the CSMA/CA logic 1051 maysense the transmission by the communications device 1030 and defertransmission for a back off period or until a subsequent time slot suchas a subsequent time slot reserved for LP-STAs.

In other situations wherein the communications devices 1030 and 1050 arenot sufficiently close to interfere with each others' communications,the CSMA/CA logic 1051 may not sense the transmission by thecommunications device 1030 and may begin to transmit during the sametime slot reserved for LP-STAs.

In further embodiments, the communications device 1055 may be a HP-STAand, in response to receiving the management frame 1014, the shepardlogic 1056 of the communications device 1055 may defer transmissionsduring the time duration(s) and may transmit a frame such as a beaconframe or other management frame as an HP transmission to inform otherHP-STAs of the time slot for the LP-STAB. For instance, once an LP-STAtransmits using CSMA-CA, if there are no collisions, a “Shepherd” withinthe HP basic service set (HP BSS), such as one or more HP-STAs or a HPaccess point (HP-AP), may discover the transmission, and set a timeduration aside during which HP-STAs should not transmit packets.

In some embodiments, the time duration may be determined by the HP-STAs.In further embodiments, the one or more HP-STAs, or the HP-AP, maycomprise shepard logic to further act as the “Shepherd” by transmittingthe time information corresponding to the time allocated to LP-STAtransmissions. The time information may also include a periodicity ofthe time duration. The time information may be included as a timeinformation element in a management frame when transmitted.

When the time information is received by a LP-STA, the LP-STA may chooseto either ignore the time information, or to adopt and transmit packetsduring the time duration indicated in the management frame to avoidcollisions with the HP-STAs. If the LP-STA adopts the time information,the shepherd logic may keep the time duration long enough for LPtransmission to occur. If the LP-STA does not adopt the timeinformation, the shepherd logic may reduce the time duration.

In many embodiments, transmission during the allocated time durationwould only be LP transmissions, including transmissions by HP-STAs andthe HP-AP, in order to ensure that the sensitivity footprint of the LPbasic service set (LP BSS) components is matched. For example, HP-STAacknowledgements (ACKs) may be LP transmissions during this period. Aframe builder 1013 of communications device 1010 may generate or selecta frame based upon a frame structure 1012 in memory 1011 ofcommunications device 1010. The medium access control (MAC) sublayerlogic 1018 may communicate with the physical layer (PHY) logic 1019 toindicate that the transmission is an LP transmission and to transmit theframe. The PHY logic 1039 of communications device 1030 may receive theframe, decapsulate the payload data and present the data to the MACsublayer logic 1038 to parse and interpret. The MAC sublayer logic 1038may determine that the frame comprises time duration information toreserve a time slot for LP-STAs and may determine whether or not toutilize the time slot.

In many embodiments, the communications device 1010 may facilitate dataoffloading. For example, communications devices that are low powersensors may include a data offloading scheme to, e.g., communicate viaWi-Fi, another communications device, a cellular network, or the likefor the purposes of reducing power consumption consumed in waiting foraccess to, e.g., a metering station and/or increasing availability ofbandwidth. Communications devices that receive data from sensors such asmetering stations may include a data offloading scheme to, e.g.,communicate via Wi-Fi, another communications device, a cellularnetwork, or the like for the purposes of reducing congestion of thenetwork 1005.

The network 1005 may represent an interconnection of a number ofnetworks. For instance, the network 1005 may couple with a wide areanetwork such as the Internet or an intranet and may interconnect localdevices wired or wirelessly interconnected via one or more hubs,routers, or switches. In the present embodiment, network 1005communicatively couples communications devices 1010, 1030, 1050, and1055.

The communication devices 1010 and 1030 comprise memory 1011 and 1031,and MAC sublayer logic 1018 and 1038, respectively. The memory 1011 and1031 may comprise a storage medium such as Dynamic Random Access Memory(DRAM), read only memory (ROM), buffers, registers, cache, flash memory,hard disk drives, solid-state drives, or the like. The memory 1011 and1031 may store the frames such as the management frames and/or the framestructures, and the memory 1011 and 1031 may store information todetermine time durations.

In many embodiments, the management frames such as beacon frames,association request frames, and association response frames may comprisefields based upon the structure of the standard frame structuresidentified in IEEE 802.11.

FIG. 1A illustrates an embodiment of a wireless network comprisingHP-STAs and LP-STAs. In this embodiment, since the two types of devicesin 802.11ah are very different in terms of transmit power but still usethe CSMA/CA channel access mechanism, in most cases, a cellularoffloading station (HP-STA) will not be able to sense transmissions of alow transmit power sensor station (LP-STA). If the cellular offloadingdevice determines that the channel is idle, it may transmitsimultaneously with the low power sensor devices and this may causecollision to the transmissions of the LP-STA. The transmission of thetime duration information by the AP2 may prevent such a situation byinforming the HP-AP1 and possibly the HP-STA1 of the reservation of thetime duration for LP-transmissions. In further embodiments, the HP-AP1may comprise shepard logic to retransmit the time duration to theHP-STA1 to cause the HP-STA1 to defer HP transmissions during the timeduration.

FIG. 1B illustrates another embodiment of a wireless network comprisinghigh power stations and low power stations. In this embodiment, when acellular offloading station (HP-STA1) is transmitting packets at a hightransmit power, a low transmit power sensor station (LP-STA2) can sensethe transmissions of the cellular offloading device and defer until thechannel is idle. This may make the low transmit power sensor station(LP-STA2) stay awake longer and consume more power. However, thetransmission of a time duration by the HP-STA or the HP-AP may allow theLP-STA2 to remain in a power conservation state until the time durationreserved for LP transmissions and thus avoid the power usage required towake only to sense a high power transmission on the channel. This isillustrated in FIG. 1B.

FIG. 1C depicts an embodiment of a management frame 1200 forcommunications between wireless communication devices such ascommunications devices 1010, 1030, 1050, and 1055 in FIG. 1. Themanagement frame 1200 may comprise a MAC header 1201, a frame body 1214,and a frame check sequence (FCS) field 1226. The MAC header 1201 maycomprise the frame control field 1202 and other MAC header fields 1208.The frame control field 1202 may be two octets and may identify the typeand subtype of the frame such as a management type and, e.g., a beaconframe subtype. The other MAC header fields 1208 may comprise, forexample, one or more address fields, identification fields, controlfields, or the like.

In some embodiments, the management frame 1200 may comprise a frame body1214. The frame body 1214 may be a variable number of octets and mayinclude data elements, control elements, or parameters and capabilities.In the present embodiment, the frame body 1214 comprises a timeinformation element 1220.

FIG. 1D illustrates an embodiment of a time information element 1300such as the time information element 1220. The time information element1300 may comprise fields such as an element identifier (ID) field 1302,a length field 1306, a device type field 1308, a duration field 1310,and a periodicity field 1314. The element ID field 1302 may be one octetand may identify the element as a time information element 1300. Thelength field 1306 may be one octet and may define the length of the timeinformation element 1300 or the length of a portion thereof. Theduration field 1310 may be, e.g., one octet and may indicate a durationof a time slot that is reserved for the devices identified in the devicetype field 1308. The periodicity field 1314 may be, e.g., one octet andmay indicate a period between reservations of the time duration. Inother words, the periodicity field 1314 may indicate a period that willpass between the occurrence of the first time duration and a second timeduration. In further embodiments, the periodicity field 1314 or anotherfield of the time information element 1300 may indicate the number ofrepetitions of the time duration.

FIG. 1E illustrates an embodiment of shepard logic 1300 such as theshepard logic 1056 illustrated in FIG. 1. The shepard logic 1300 maycomprise detection logic 1305 to detect a communication by a LP-STA suchas the communications device 1030 and may defer HP transmissions duringa time duration in response to detecting the LP transmission. Forexample, once an LP-STA transmits using CSMA-CA, if there are nocollisions, the detection logic 1305, which may reside within one ormore HP-STAs of an HP BSS, may detect the LP transmission and set a timeduration aside during which HP STAs should not transmit packets. Thetime duration may be determined in any manner known such as interpretinga network allocation vector (NAV) and may be set or predetermined toassure that the LP transmission has completed prior to initiating an HPtransmission. In some embodiments, the shepard logic 1300 may compriseretransmission logic 1320 to retransmit or otherwise communicate thetime duration such as a NAV to other HP STAs to reserve the timeduration for the LP transmission.

In several embodiments, the scheduling logic 1315 of one or moreHP-STAs, or the HP-AP, may transmit a management frame with a timeinformation element such as the management frame and time informationelements illustrated in FIGS. 1C-D. When the time information isreceived by an LP-STA, the LP-STA may choose to either ignore the timeinformation, or to adopt and transmit packets during the time durationindicated in the management frame to avoid collisions with HPtransmissions of the HP-STAs. If the LP-STA adopts the time information,the scheduling logic 1315 may defer HP transmissions for the full timeduration to avoid a collision with the LP transmission. For instance, anLP-STA or an LP-AP may acknowledge the time slot allocation to confirmthat the time information is being adopted. In some embodiments, theLP-AP may acknowledge, respond, or otherwise indicate that the LP-STAsadopt the time information in an HP transmission so that HP-STAs thatmight otherwise not detect the LP transmission can detect the adoptionof the time information.

If the LP-STA does not adopt the time information, the scheduling logic1315 may reduce the time duration. Transmission during the allocatedtime duration would only be LP transmissions, including transmissions byHP-STAs and the HP-AP, in order to ensure that the sensitivity footprintof the LP BSS components is matched. For example, HP-STAacknowledgements (ACKs) may be LP transmissions during the allocatedtime duration.

Referring again to FIG. 1, the MAC sublayer logic 1018, 1038 maycomprise logic to implement functionality of the MAC sublayer of thedata link layer of the communications device 1010, 1030. The MACsublayer logic 1018, 1038 may generate the frames such as managementframes, data frames, and control frames, and may communicate with thePHY logic 1019, 1039 to transmit the frames 1014, 1034. The PHY logic1019, 1039 may generate physical layer protocol data units (PPDUs) basedupon the frames 1014, 1034. More specifically, the frame builders 1013and 1033 may generate the frames 1014, 1034 and data unit builders ofthe PHY logic 1019, 1039 may encapsulate the frames 1014, 1034 withpreambles to generate PPDUs for transmission via a physical layer devicesuch as the transceivers (RX/TX) 1020 and 1040.

The frame 1014, also referred to as a MAC layer Service Data Unit(MSDU), may comprise a management frame. For example, frame builder 1013may generate a management frame such as the beacon frame to identify thecommunications device 1010 as having capabilities such as supported datarates, privacy settings, quality of service support (QoS), power savingfeatures, cross-support, and a service set identification (SSID) of thenetwork to identify the network to the communications device 1030.

The communications devices 1010, 1030, 1050, and 1055 may each comprisea transceiver such as transceivers 1020 and 1040. Each transceiver 1020,1040 comprises a radio comprising an RF transmitter and an RF receiver.Each RF transmitter impresses digital data onto an RF frequency fortransmission of the data by electromagnetic radiation. An RF receiverreceives electromagnetic energy at an RF frequency and extracts thedigital data therefrom.

FIG. 1 may depict a number of different embodiments including aMultiple-Input, Multiple-Output (MIMO) system with, e.g., four spatialstreams, and may depict degenerate systems in which one or more of thecommunications devices 1010, 1030, 1050, and 1055 comprise a receiverand/or a transmitter with a single antenna including a Single-Input,Single Output (SISO) system, a Single-Input, Multiple Output (SIMO)system, and a Multiple-Input, Single Output (MISO) system.

In many embodiments, transceivers 1020 and 1040 implement orthogonalfrequency-division multiplexing (OFDM). OFDM is a method of encodingdigital data on multiple carrier frequencies. OFDM is afrequency-division multiplexing scheme used as a digital multi-carriermodulation method. A large number of closely spaced orthogonalsub-carrier signals are used to carry data. The data is divided intoseveral parallel data streams or channels, one for each sub-carrier.Each sub-carrier is modulated with a modulation scheme at a low symbolrate, maintaining total data rates similar to conventionalsingle-carrier modulation schemes in the same bandwidth.

An OFDM system uses several carriers, or “tones,” for functionsincluding data, pilot, guard, and nulling. Data tones are used totransfer information between the transmitter and receiver via one of thechannels. Pilot tones are used to maintain the channels, and may provideinformation about time/frequency and channel tracking. Guard tones maybe inserted between symbols such as the short training field (STF) andlong training field (LTF) symbols during transmission to avoidinter-symbol interference (ISI), which might result from multi-pathdistortion. These guard tones also help the signal conform to a spectralmask. The nulling of the direct component (DC) may be used to simplifydirect conversion receiver designs.

In some embodiments, the communications device 1010 optionally comprisesa Digital Beam Former (DBF) 1022, as indicated by the dashed lines. TheDBF 1022 transforms information signals into signals to be applied via aradio to elements of an antenna array 1024. The antenna array 1024 is anarray of individual, separately excitable antenna elements. The signalsapplied to the elements of the antenna array 1024 cause the antennaarray 1024 to radiate one to four spatial channels. Each spatial channelso formed may carry information to one or more of the communicationsdevices 1030, 1050, and 1055. Similarly, the communications device 1030comprises a transceiver 1040 to receive and transmit signals from and tothe communications device 1010. The transceiver 1040 may comprise anantenna array 1044 and, optionally, a DBF 1042.

FIG. 2 depicts an embodiment of an apparatus to generate, communicate,transmit, receive, communicate, and interpret a frame. The apparatuscomprises a transceiver 200 coupled with medium access control (MAC)sublayer logic 201. The MAC sublayer logic 201 may determine a framesuch as a management frame and transmit the frame to the physical layer(PHY) logic 250. The PHY logic 250 may determine the PPDU by determininga preamble and encapsulating the frame with a preamble to transmit viatransceiver 200.

In many embodiments, the MAC sublayer logic 201 may comprise a framebuilder 202 to generate frames (MPDUs). The MAC sublayer logic 201 maythen receive and parse and interpret a response frame. In manyembodiments of LP-APs, the MAC sublayer logic 201 may comprise logic togenerate a management frame such as a beacon frame and instruct the PHYlogic 250 to transmit the management frame in an HP transmission. Inseveral embodiments of HP-STAs, the MAC sublayer logic 201 may compriselogic to generate a management frame such as a beacon frame with a timeinformation element and instruct the PHY logic 250 to transmit themanagement frame. In many of such embodiments, the MAC sublayer logic201 may comprise logic to receive and process a response indicatingwhether the LP-STA adopts the time duration and to interpret theresponse to determine whether to maintain the time duration for LPtransmissions or to reduce the time duration. For instances in which theLP-STA such as an LP-AP adopts the time duration, the MAC sublayer logic201 may defer HP transmissions for the time duration. On the other hand,if the LP-STA does not respond or responds with an indication that theLP-STA does not adopt the time duration, the MAC sublayer logic 201 mayreduce or eliminate the time duration.

The PHY logic 250 may comprise a data unit builder 203. The data unitbuilder 203 may determine a preamble and the PHY logic 250 mayencapsulate the MPDU with the preamble to generate a PPDU. In manyembodiments, the data unit builder 203 may create the preamble basedupon communications parameters chosen through interaction with adestination communications device.

In many embodiments, the PHY logic 250 may change the transmission powerbetween an LP transmission and an HP transmission. For instance, inresponse to an indication from the MAC sublayer logic 201 to increasethe power of a transmission from an LP transmission to an HPtransmission, the PHY logic 250 may change the transmission power. Insome embodiments, the default transmission power may be LP and the PHYlogic 250 may change the transmission power to HP for a singletransmission, reverting back to LP transmissions absent additionalinstructions from the MAC sublayer logic 201.

The transceiver 200 comprises a receiver 204 and a transmitter 206. Thetransmitter 206 may comprise one or more of an encoder 208, a modulator210, an OFDM 212, and a DBF 214. The encoder 208 of the transmitter 206receives and encodes data destined for transmission from the MACsublayer logic 201 with, e.g., a binary convolutional coding (BCC), alow density parity check coding (LDPC), and/or the like. The modulator210 may receive data from the encoder 208 and may impress the receiveddata blocks onto a sinusoid of a selected frequency via, e.g., mappingthe data blocks into a corresponding set of discrete amplitudes of thesinusoid, or a set of discrete phases of the sinusoid, or a set ofdiscrete frequency shifts relative to the frequency of the sinusoid. Theoutput of the modulator 210 is fed to an orthogonal frequency divisionmultiplexer (OFDM) 212, which impresses the modulated data from themodulator 210 onto a plurality of orthogonal subcarriers. And, theoutput of the OFDM 212 may be fed to the digital beam former (DBF) 214to form a plurality of spatial channels and steer each spatial channelindependently to maximize the signal power transmitted to and receivedfrom each of a plurality of user terminals.

The transceiver 200 may also comprise diplexers 216 connected to antennaarray 218. Thus, in this embodiment, a single antenna array is used forboth transmission and reception. When transmitting, the signal passesthrough diplexers 216 and drives the antenna with the up-convertedinformation-bearing signal. During transmission, the diplexers 216prevent the signals to be transmitted from entering receiver 204. Whenreceiving, information bearing signals received by the antenna arraypass through diplexers 216 to deliver the signal from the antenna arrayto receiver 204. The diplexers 216 then prevent the received signalsfrom entering transmitter 206. Thus, diplexers 216 operate as switchesto alternately connect the antenna array elements to the receiver 204and the transmitter 206.

The antenna array 218 radiates the information bearing signals into atime-varying, spatial distribution of electromagnetic energy that can bereceived by an antenna of a receiver. The receiver can then extract theinformation of the received signal.

The transceiver 200 may comprise a receiver 204 for receiving,demodulating, and decoding information bearing signals. The receiver 204may comprise one or more of a DBF 220, an OFDM 222, a demodulator 224and a decoder 226. The received signals are fed from antenna elements218 to a Digital Beam Former (DBF) 220. The DBF 220 transforms N antennasignals into L information signals. The output of the DBF 220 is fed tothe OFDM 222. The OFDM 222 extracts signal information from theplurality of subcarriers onto which information-bearing signals aremodulated. The demodulator 224 demodulates the received signal,extracting information content from the received signal to produce anun-demodulated information signal. And, the decoder 226 decodes thereceived data from the demodulator 224 and transmits the decodedinformation, the MPDU, to the MAC sublayer logic 201.

After receiving a frame, the MAC sublayer logic 201 may access framestructures in memory to parse the frame. Based upon this information,the MAC sublayer logic 201 may determine a time duration forcommunicating for LP-STA s. In some embodiments, the MAC sublayer logic201 may communicate with an LP-AP or another LP-STA during the timeduration.

Persons of skill in the art will recognize that a transceiver maycomprise numerous additional functions not shown in FIG. 2 and that thereceiver 204 and transmitter 206 can be distinct devices rather thanbeing packaged as one transceiver. For instance, embodiments of atransceiver may comprise a Dynamic Random Access Memory (DRAM), areference oscillator, filtering circuitry, synchronization circuitry, aninterleaver and a deinterleaver, possibly multiple frequency conversionstages and multiple amplification stages, etc. Further, some of thefunctions shown in FIG. 2 may be integrated. For example, digital beamforming may be integrated with orthogonal frequency divisionmultiplexing. In some embodiments, for instance, the transceiver 200 maycomprise one or more processors and memory including code to performfunctions of the transmitter 206 and/or receiver 204.

FIGS. 3A-C depict embodiments of flowcharts 300, 350, and 370 tocoordinate communications. Referring to FIG. 3A, the flowchart 300begins with generating a management frame with a time informationelement (element 305). In some embodiments, an LP-AP may generate amanagement frame such as a beacon frame to communicate a time duration.In some embodiments, the LP-AP may generate a management framecomprising a periodicity associated with the time duration. In furtherembodiments, the management frame may comprise an explicit or implicitassociation between the time duration and a reservation of a time slotfor a LP device type or LP transmissions. And in several embodiments,the LP-AP may comprise MAC sublayer logic to instruct the PHY logic totransmit the management frame at a high transmit power to increase thenumber of HP-STAs that detect and interpret the management frame todefer HP transmissions during the time duration.

In further embodiments, an HP-AP or other HP-STA may generate amanagement frame such as a beacon frame to communicate a time durationand, in some embodiments, a periodicity to reserve a time slot for LPtransmissions. In some embodiments, the time information element maycomprise a device type field to indicate that the time duration isreserved for the particular device type. In several embodiments, theHP-AP or other HP-STA may comprise MAC sublayer logic to await aresponse to the management frame to determine whether the LP-STA adoptsthe time slot indicated by the time duration.

After generating the management frame, the PHY logic may encapsulate themanagement frame with a preamble to generate a PPDU (element 310). Andthe PHY may then transmit the PPDU via an antenna or an antenna array(element 315).

In FIG. 3B, the flowchart 350 begins with receiving a management framewith a time information element (element 355). In some embodiments, theMAC sublayer logic of an HP-STA may receive the management frame withthe time information element and parse and interpret the managementframe to determine that the HP-STA should defer HP transmissions or, insome embodiments, all transmissions for a time duration included in thetime information element (element 360). In some embodiments, parsing andinterpreting the time information element may involve parsing andinterpreting a value for a periodicity that indicates the deferment tothe LP transmissions for the time duration repeated periodically. Inmany embodiments, the HP-STA may, in response, defer transmissions or atleast HP transmissions for the time duration or the periodicallyreoccurring time duration (element 365).

In FIG. 3C, the flowchart 370 begins with receiving a management framewith a time information element (element 375). In some embodiments, theMAC sublayer logic of an LP-STA may receive the management frame withthe time information element and parse and interpret the managementframe to determine that the LP-STA may adopt a time duration or a timeduration that periodically repeats to avoid collisions with HPtransmissions (element 380). In particular, the time duration mayrepresent an allocated time slot during which one or more HP-STAs aredeferring HP transmissions to facilitate LP transmissions.

If the LP-STA determines to adopt the time slot indicated by the timeduration, the LP-STA may transmit an LP transmission during the timeduration (element 385). In some embodiments, the LP-STA may be an LP-APand the LP-AP may determine whether or not the time duration may beadopted by LP-STAs within the BSS of the LP-AP.

FIG. 4 depicts an embodiment of flowchart 450 to receive and interpretcommunications to coordinate transmissions of different types of deviceson a wireless network such as the system described in conjunction withand illustrated in FIGS. 1 and 1A-E. The flowchart 450 begins withreceiving a transmission of an LP-STA (element 455). Receiving atransmission of an LP-STA may comprise detecting an LP transmission byan HP-STA. The HP-STA may determine a time duration in response to theLP transmission, the time duration to match or exceed the duration ofthe LP transmission, and defer transmission for a time duration (element460). In some embodiments, the time duration may be estimated, fixedand/or predetermined. In some embodiments, the time duration may becalculated or estimated based upon content of the LP transmission. Insome embodiments, the time duration may be determined by other means.

In the present embodiment, after deferring for the duration, shepardlogic of the HP-STA may determine a time duration for which the LP STAsmay transmit and the HP-STA may generate and transmit a management frameindicating a time duration associated with low transmit powercommunication to instruct high-power communication devices to defer hightransmit power transmissions for the time duration (element 465). Insome embodiments, generating and transmitting a management frame maycomprise transmitting, by the HP-STA, the time duration in a timeinformation element of a management frame with a device type field valueindicating that the time duration comprises a time slot allocated to LPtransmissions. In further embodiments, generating and transmitting themanagement frame may comprise transmitting, by the HP-STA, a periodicityvalue in the time information element to associate the time durationwith the periodicity to establish a periodic time slot allocation forlow transmit power transmissions.

After transmitting the management frame, the HP-STA may determinewhether or not an LP-STA adopted the time duration (element 467). Afterdetermining that the LP station adopts the time duration, the HP-STA maydefer HP transmissions for the time duration (element 470). In someembodiments, determining that the LP station adopts the time durationmay involve receiving an indication that an LP-STA adopts the timeinformation and deferring high transmit power transmissions until theexpiration of the time duration.

On the other hand, after determining that the LP station does not adoptthe time duration, the HP-STA may reduce the time duration during whichto defer HP transmissions (element 480) by, e.g., updating the timeduration with a reduced time duration, transmitting the reduced timeduration to other HP-STAs to update their time duration, and/or thelike.

The following examples pertain to further embodiments. One examplecomprises a method. The method may involve generating, by a firstcommunications device, a frame indicating a time duration associatedwith low transmit power communication to instruct high-powercommunication devices to defer high transmit power transmissions for thetime duration; and transmitting, by the first communications device, theframe.

In some embodiments, the method may further comprise transmitting, bythe antenna, the frame encapsulated by the preamble. In someembodiments, the method may further comprise detecting, by shepard logicof a high-power communications device, the low power communication and,in response, deferring high transmit power transmissions during the timeduration, wherein the first communication device comprises a high-powercommunications device. In many embodiments, the method may furthercomprise transmitting, by the high-power communications device, the timeduration in a time information element of a management frame with adevice type field value indicating that the time duration comprises atime slot allocated to low transmit power transmissions. In severalembodiments, the method may further comprise transmitting, by thehigh-power communications device, a periodicity value in the timeinformation element to associate the time duration with the periodicityto establish a periodic time slot allocated to low transmit powertransmissions. In some embodiments, the method may further comprisereceiving an indication that a low-power communications device adoptsthe time information and deferring high transmit power transmissionsuntil the expiration of the time duration. In some embodiments, themethod may further comprise receiving an indication that a low-powercommunications device does not adopt the time duration and, in response,reducing deferment of the high-power transmissions to less than the timeduration. In some embodiments, the method may further comprisetransmitting, by the high-power communications device, low transmitpower transmissions during the time duration. In several embodiments,transmitting, by the first communications device, comprises transmittingby an access point with a high transmit power, wherein the framecomprises a management frame with a time information element, the timeinformation element comprising a device type field comprising anindication of a low-power device and a time duration field comprisingthe time duration. And in some embodiments, the method may furthercomprise transmitting, by the access point, a periodicity associatedwith the time duration in the frame.

At least one computer program product for communication of a packet witha frame, the computer program product comprising a computer useablemedium having a computer useable program code embodied therewith, thecomputer useable program code comprising computer useable program codeconfigured to perform operations, the operations to carry out a methodaccording to any one or more or all of embodiments of the methoddescribed above.

At least one system comprising hardware and code may carry out a methodaccording to any one or more or all of embodiments of the methoddescribed above.

Another example comprises an apparatus. The apparatus may comprise amedium access control sublayer logic to generate a frame indicating atime duration associated with low transmit power communication toinstruct high-power communication devices to defer high transmit powertransmissions for the time duration; and a physical layer logic toencapsulate and transmit the frame.

In some embodiments, the apparatus may further comprise an antenna totransmit the frame encapsulated by the preamble. In some embodiments,the medium access control sublayer logic comprises shepard logic todetect the low power communication and, in response, defer high transmitpower transmissions during the time duration, wherein the firstcommunication device comprises a high-power communications device. Insome embodiments, the medium access control sublayer logic comprisesshepard logic to transmit the time duration in a time informationelement of a management frame with a device type field value indicatingthat the time duration comprises a time slot allocated to low transmitpower transmissions. In some embodiments, the medium access controlsublayer logic comprises logic to transmit a periodicity value in thetime information element to associate the time duration with theperiodicity to establish a periodic time slot allocated to low transmitpower transmissions. In some embodiments, the medium access controlsublayer logic comprises shepard logic to receive an indication that alow-power communications device adopts the time information and deferhigh transmit power transmissions until the expiration of the timeduration. In some embodiments, the medium access control sublayer logiccomprises shepard logic to receive an indication that a low-powercommunications device does not adopt the time information and to reducedeferment of the high transmit power transmissions to less than the timeduration in response. In some embodiments, the medium access controlsublayer logic comprises shepard logic to transmit, by a high-powercommunications device, low transmit power transmissions during the timeduration. In some embodiments, the medium access control sublayer logiccomprises logic to transmit, by an access point, a periodicityassociated with the time duration in the frame. And in some embodimentsof the apparatus, the medium access control sublayer logic compriseslogic to transmit, by an access point, the frame with a high transmitpower, wherein the frame comprises a management frame with a timeinformation element, the time information element comprising a devicetype field comprising an indication of a low-power device and a timeduration field comprising the time duration.

Another example comprises a system. The system may comprise a mediumaccess control sublayer logic to generate a frame indicating a timeduration associated with low transmit power communication to instructhigh-power communication devices to defer high transmit powertransmissions for the time duration; and a physical layer logic toencapsulate transmit the frame; and an antenna coupled with the physicallayer logic to transmit the frame.

Another example comprises a program product. The program product tocoordinate transmissions of different types of devices on a wirelessnetwork may comprise a storage medium comprising instructions to beexecuted by a processor-based device, wherein the instructions, whenexecuted by the processor-based device, perform operations, theoperations comprising: generating, by a first communications device, aframe indicating a time duration associated with low transmit powercommunication to instruct high-power communication devices to defer hightransmit power transmissions for the time duration; and transmitting, bythe first communications device, the frame.

In some embodiments, the operations may further comprise transmitting,by the antenna, the frame encapsulated by the preamble. In someembodiments, the operations may further comprise detecting, by shepardlogic of a high-power communications device, the low power communicationand, in response, deferring high transmit power transmissions during thetime duration, wherein the first communication device comprises ahigh-power communications device. In many embodiments, the operationsmay further comprise transmitting, by the high-power communicationsdevice, the time duration in a time information element of a managementframe with a device type field value indicating that the time durationcomprises a time slot allocated to low transmit power transmissions. Inseveral embodiments, the operations may further comprise transmitting,by the high-power communications device, a periodicity value in the timeinformation element to associate the time duration with the periodicityto establish a periodic time slot allocated to low transmit powertransmissions. In some embodiments, the operations may further comprisereceiving an indication that a low-power communications device adoptsthe time information and deferring high transmit power transmissionsuntil the expiration of the time duration. In some embodiments, theoperations may further comprise receiving an indication that a low-powercommunications device does not adopt the time duration and, in response,reducing deferment of the high-power transmissions to less than the timeduration. In some embodiments, the operations may further comprisetransmitting, by the high-power communications device, low transmitpower transmissions during the time duration. In several embodiments,transmitting, by the first communications device, comprises transmittingby an access point with a high transmit power, wherein the framecomprises a management frame with a time information element, the timeinformation element comprising a device type field comprising anindication of a low-power device and a time duration field comprisingthe time duration. And in some embodiments, the operations may furthercomprise transmitting, by the access point, a periodicity associatedwith the time duration in the frame.

Another example comprises a method. The method may involve receiving, bya medium access control sublayer logic of a communications device, aframe comprising a time information element, the time informationelement comprising a time duration, the time duration indicating a timeslot allocated for low transmit power transmissions during which hightransmit power transmissions are to be deferred; and communicating, bythe communications device, during the time duration.

In some embodiments, receiving the frame comprising the time informationelement comprises receiving the time information element comprising adevice type associated with the time duration, the device typeindicating that the time slot is allocated for low-power communicationsdevices. In some embodiments, receiving the frame comprising the timeinformation element comprises receiving the time information elementcomprising a periodicity associated with the time duration, theperiodicity indicating a periodicity of the time slot allocated for lowtransmit power transmissions during which high transmit powertransmissions are to be deferred. And in many embodiments,communicating, by the communications device, during the time durationcomprises storing an indication of the time duration and the periodicityin memory and communicating during more than one of the time slots.

At least one computer program product for communication of a packet witha frame, the computer program product comprising a computer useablemedium having a computer useable program code embodied therewith, thecomputer useable program code comprising computer useable program codeconfigured to perform operations, the operations to carry out a methodaccording to any one or more or all of embodiments of the methoddescribed above.

At least one system comprising hardware and code may carry out a methodaccording to any one or more or all of embodiments of the methoddescribed above.

Another example comprises an apparatus. The apparatus may comprise amedium access control sublayer logic to receive a frame comprising atime information element, the time information element comprising a timeduration, the time duration indicating a time slot allocated forlow-power communications and during which high-power communications areto be deferred; and a physical layer logic to communicate during thetime slot.

In some embodiments, the apparatus may further comprise an antennacoupled with the physical layer logic to transmit a communication duringthe time slot. In some embodiments, the apparatus may further comprisememory coupled with the medium access control sublayer logic, the mediumaccess control sublayer logic to store an indication of the time slot inthe memory. And in some embodiments, the medium access control sublayerlogic comprises logic to receive the time information element comprisinga periodicity associated with the time duration, the periodicityindicating a periodicity of the time slot allocated for low-powercommunications and during which high-power communications are to bedeferred.

Another example comprises a system. The system may comprise a mediumaccess control sublayer logic to receive a frame comprising a timeinformation element, the time information element comprising a timeduration, the time duration indicating a time slot allocated forlow-power communications and during which high-power communications areto be deferred; and a physical layer logic to communicate during thetime slot; and an antenna coupled with the physical layer logic toreceive the frame.

Another example comprises a program product. The program product tocoordinate transmissions of different types of devices on a wirelessnetwork may comprise a storage medium comprising instructions to beexecuted by a processor-based device, wherein the instructions, whenexecuted by the processor-based device, perform operations, theoperations comprising: receiving, by a medium access control sublayerlogic of a communications device, a frame comprising a time informationelement, the time information element comprising a time duration, thetime duration indicating a time slot allocated for low transmit powertransmissions during which high transmit power transmissions are to bedeferred; and communicating, by the communications device, during thetime duration.

In some embodiments of the program product, receiving the framecomprising the time information element comprises receiving the timeinformation element comprising a device type associated with the timeduration, the device type indicating that the time slot is allocated forlow-power communications devices. In some embodiments, receiving theframe comprising the time information element comprises receiving thetime information element comprising a periodicity associated with thetime duration, the periodicity indicating a periodicity of the time slotallocated for low transmit power transmissions during which hightransmit power transmissions are to be deferred. And in someembodiments, communicating, by the communications device, during thetime duration comprises storing an indication of the time duration andthe periodicity in memory and communicating during more than one of thetime slots.

In some embodiments, some or all of the features described above and inthe claims may be implemented in one embodiment. For instance,alternative features may be implemented as alternatives in an embodimentalong with logic or selectable preference to determine which alternativeto implement. Some embodiments with features that are not mutuallyexclusive may also include logic or a selectable preference to activateor deactivate one or more of the features. For instance, some featuresmay be selected at the time of manufacture by including or removing acircuit pathway or transistor. Further features may be selected at thetime of deployment or after deployment via logic or a selectablepreference such as a dipswitch, e-fuse, or the like. Still furtherfeatures may be selected by a user after via a selectable preferencesuch as a software preference, an c-fuse, or the like.

In some embodiments, some or all of the features described above and inthe claims may be implemented in one embodiment. For instance,alternative features may be implemented as alternatives in an embodimentalong with logic or selectable preference to determine which alternativeto implement. Some embodiments with features that are not mutuallyexclusive may also include logic or a selectable preference to activateor deactivate one or more of the features. For instance, some featuresmay be selected at the time of manufacture by including or removing acircuit pathway or transistor. Further features may be selected at thetime of deployment or after deployment via logic or a selectablepreference such as a dipswitch or the like. A user after via aselectable preference such as a software preference, a dipswitch, or thelike may select still further features.

A number of embodiments may have one or more advantageous effects. Forinstance, some embodiments may offer reduced MAC header sizes withrespect to standard MAC header sizes. Further embodiments may includeone or more advantageous effects such as smaller packet sizes for moreefficient transmission, lower power consumption due to less data trafficon both the transmitter and receiver sides of communications, lesstraffic conflicts, less latency awaiting transmission or receipt ofpackets, and the like.

Another embodiment is implemented as a program product for implementingsystems, apparatuses, and methods described with reference to FIGS. 1-4.Embodiments can take the form of an entirely hardware embodiment, asoftware embodiment implemented via general purpose hardware such as oneor more processors and memory, or an embodiment containing bothspecific-purpose hardware and software elements. One embodiment isimplemented in software or code, which includes but is not limited tofirmware, resident software, microcode, or other types of executableinstructions.

Furthermore, embodiments can take the form of a computer program productaccessible from a machine-accessible, computer-usable, orcomputer-readable medium providing program code for use by or inconnection with a computer, mobile device, or any other instructionexecution system. For the purposes of this description, amachine-accessible, computer-usable, or computer-readable medium is anyapparatus or article of manufacture that can contain, store,communicate, propagate, or transport the program for use by or inconnection with the instruction execution system or apparatus.

The medium may comprise an electronic, magnetic, optical,electromagnetic, or semiconductor system medium. Examples of amachine-accessible, computer-usable, or computer-readable medium includememory such as volatile memory and non-volatile memory. Memory maycomprise, e.g., a semiconductor or solid-state memory like flash memory,magnetic tape, a removable computer diskette, a random access memory(RAM), a read-only memory (ROM), a rigid magnetic disk, and/or anoptical disk. Current examples of optical disks include compactdisk-read only memory (CD-ROM), compact disk-read/write memory (CD-R/W),digital video disk (DVD)-read only memory (DVD-ROM), DVD-random accessmemory (DVD-RAM), DVD-Recordable memory (DVD-R), and DVD-read/writememory (DVD-R/W).

An instruction execution system suitable for storing and/or executingprogram code may comprise at least one processor coupled directly orindirectly to memory through a system bus. The memory may comprise localmemory employed during actual execution of the code, bulk storage suchas dynamic random access memory (DRAM), and cache memories which providetemporary storage of at least some code in order to reduce the number oftimes code must be retrieved from bulk storage during execution.

Input/output or I/O devices (including but not limited to keyboards,displays, pointing devices, etc.) can be coupled to the instructionexecution system either directly or through intervening I/O controllers.Network adapters may also be coupled to the instruction execution systemto enable the instruction execution system to become coupled to otherinstruction execution systems or remote printers or storage devicesthrough intervening private or public networks. Modem, Bluetooth™,Ethernet, Wi-Fi, and WiDi adapter cards are just a few of the currentlyavailable types of network adapters.

What is claimed is:
 1. A wireless access point device that controlsaccess by a first type of device to reduce power consumption by a secondtype of device caused by contentions between the first type of deviceand the second type of device, comprising: at least one memory thatstores computer-executable instructions; and at least one processorconfigured to access the at least one memory, wherein the at least oneprocessor is configured to execute the computer-executable instructionsto: determine a time duration indicative of time reserved for the secondtype of device to communicate with the wireless access point device,wherein the time duration is further indicative of a duration of a timeslot allocated to the second type of device; determine a periodicity ofthe time duration; generate a beacon frame including the time duration,an indication of the periodicity, and an indication of the second typeof device for which the time duration is reserved for communication withthe wireless access point device, wherein the beacon frame includes aninformation element comprising a duration field including the timeduration of the time slot, a periodicity field including the periodicityof the time slot, and a device field including indication of a type ofdevice; and cause to send the beacon frame.
 2. The wireless access pointdevice of claim 1, wherein the second type of device includes a sensor.3. The wireless access point device of claim 1, wherein the informationelement is configured to restrict the first type of device fromcommunicating with the wireless access point device during the timeduration.
 4. The wireless access point device of claim 1, wherein the atleast one processor is further configured to execute thecomputer-executable instructions to identify a communication receivedfrom a station of the second type of device during the time duration,the communication indicative of an adoption by the station of the timeduration.
 5. The wireless access point device of claim 1, wherein the atleast one processor further configured to execute thecomputer-executable instructions to: determine an absence of acommunication from the second type of device during the time durationindicated in the beacon frame, determine a second time duration that isshorter than the time duration, generate a second beacon frame includingthe second time duration, and cause to send the second beacon frame. 6.The wireless access point device of claim 1, wherein the at least oneprocessor is further configured to execute the computer-executableinstructions to detect, prior to the determination of the time duration,a transmission by a station of the second type of device.
 7. Thewireless access point device of claim 1, further comprising atransceiver configured to send and receive wireless signals.
 8. Thewireless access point device of claim 7, further comprising one or moreantennas coupled to the transceiver.
 9. A non-transitorycomputer-readable medium storing computer-executable instructions that,when executed by at least one processor, configure the at least oneprocessor to perform operations comprising: determining a time durationindicative of time allocated for a first type of device to communicatewith a wireless access point device, and during which time a second typeof device is restricted from communicating with the wireless accesspoint device, wherein the time duration is further indicative of aduration of a time slot allocated to the first type of device;determining a periodicity of the time duration; generating a beaconframe including the time duration, an indication of the periodicity, andan indication of the first type of device for which the time duration isallocated for communications with the wireless access point device,wherein the beacon frame includes an information element comprising aduration field for the time duration of the time slot, a periodicityfield for the periodicity of the time slot, and a device field for thetype of device; and causing to send the beacon frame.
 10. Thenon-transitory computer-readable medium of claim 9, wherein the firsttype of device includes a sensor.
 11. The non-transitorycomputer-readable medium of claim 9, wherein the information element isconfigured to prevent the second type of device from communicating withthe wireless access point device when the first type of device iscommunicating with the wireless access point device.
 12. Thenon-transitory computer-readable medium of claim 9, the processorfurther configured to perform operations comprising identifying acommunication received during the time duration from a station of thesecond type of device, the communication indicative of an adoption bythe station of the time duration.
 13. The non-transitorycomputer-readable medium of claim 9, the processor further configured toperform operations comprising: determining an absence of a communicationfrom the first type of device during the time duration in the beaconframe, determining a second time duration that is shorter than the timeduration, generating a second beacon frame including the second timeduration, and causing to send the second beacon frame.
 14. Thenon-transitory computer-readable medium of claim 9, the processorfurther configured to perform operations comprising detecting, prior tothe determination of the time duration, a transmission by a station ofthe first type of device.
 15. A method for limiting access to a wirelessaccess point by a first type of device to reduce power consumption by asecond type of device caused by contentions between the first type ofdevice and the second type of device, comprising: determining a timeduration indicative of time allocated for the second type of device tocommunicate with a wireless access point device, and during which timethe first type of device is restricted from communicating with thewireless access point device, wherein the time duration is indicative ofa duration of a time slot allocated to the first type of device;determining a periodicity of the time duration; generating a beaconframe including the time duration, an indication of the periodicity, andan indication of the second type of device for which the time durationis allocated for communications with the access point device, whereinthe beacon frame includes an information element comprising a durationfield for the time duration of the time slot, a periodicity field forthe periodicity of the time slot, and a device field for the type ofdevice; and causing to send the beacon frame.
 16. The method of claim15, wherein the first type of device includes a sensor.
 17. The methodof claim 15, wherein the information element is configured to preventthe first type of device from communicating with the wireless accesspoint device when the second type of device is communicating with thewireless access point device.